Mars is one of the most explored worlds in the Solar System, from orbiting satellites to landing probes to moving robot rovers. Since the beginning of the use of the telescope in the early 1600's, people have been in love, and even afraid of Mars. Through the telescope, ancient astronomers could see what appeared to be season changes and water canals. These things led people to believe that there was probably life on Mars, even advanced intelligent life.

Is there life on Mars?
The quick answer to this question is no life has been found. In recent years, NASA has sent probes, which are satellites that actually land, to explore the planet's surface. One important part of the mission of these probes has been to look for life. They take little scoops of dirt and perform a series of experiments. By looking at the way the dirt reacts in these experiments, scientists can determine whether or not there is anything alive in the sample. So far, no life has been found on Mars.

Has there ever been life on Mars?
Have you ever visited the Grand Canyon, with its brown, yellow, red and white cliffs, pillars and alcoves? What created this amazing scenery? Two relentless tireless forces worked together in its formation over millions of years. These forces were wind and water. The canyon is a monument to the power of the flowing waters of the Colorado River. What does any of this have to do with life on Mars? Well, as big and beautiful as the Grand Canyon is, there is a canyon even bigger and more beautiful. This canyon is so big that if placed in the United States it would stretch from one end to the other.

Why is that important? Well, we must ask ourselves, how was this canyon created? Probably by the same two forces that created the Grand Canyon here on Earth, wind and water. Today there is no flowing water on Mars. But had there been at one time long ago as suggested by this canyon, then it is very possible that life once existed on Mars.

While the experiments looking for life on Mars have returned no positive results, there has been some evidence found which seems to support ancient life on Mars.

Will there ever be life on Mars?
This question can be answered with an almost certain yes. NASA's Mars program is focused on that very issue. Finding ways to get humans to Mars, and then keeping them alive once they arrive. Whether or not humans will live long term on Mars is hard to say, but it appears very likely that we will at least visit.

Missions to Mars
The Soviet Union was the first country to attempt launching spacecraft to Mars. They made five attempts beginning in 1960 before NASA began their attempts in 1964. None of these were successful. Some failed on launch. Others launched successfully but contact was lost or other malfunctions occurred. These were not, however, the only attempts the Soviet Union made at launching spacecraft to Mars. They made more attempts through the rest of the 1960s and into the 1970s, and there were 2 attempts in 1988. Some of these missions were successful, like the Mars 3. It was an orbiter sent to Mars that launched another craft that landed on the surface of the planet. This craft landed successfully but only worked for a short time because the instruments stopped working. The orbiter, however, continued to orbit the planet along with the Mars 2 orbiter that was already orbiting the planet. These 2 orbiters collected a lot of information about Mars' atmosphere, temperature, terrain, magnetic field, and sent back a lot of pictures.

In 1964, NASA began launching missions to Mars. On November 5, 1964, Mariner 3 was launched. It encountered problems after it left Earth's atmosphere and was not able to complete its mission. Mariner 4 lifted off on November 28, 1964. It traveled some 325 million miles towards this red sibling planet. The pictures Mariner 4 sent back were fuzzy, but they were clear enough to shatter current scientific belief. Scientists expected to find an intelligent species with cities and artificial canals. Instead they found a dead planet that looked much like the Moon, only red.

Image: NASA/JPL-Caltech

Mariner 6 began its journey towards Mars on February 25, 1969. Then, just a month later on March 27, 1969, Mariner 7 followed the same path. The two satellites could gather more than 35 times the amount of data that Mariner 4 had gathered. They shot a total of 199 pictures all together, adding a great wealth of knowledge about the planet.

Mars 2 and Mars 3 were sent by Russia in late May of 1971. A couple days after this, NASA sent Mariner 9. Mariner 8 had failed, falling into the Atlantic Ocean shortly after lift off. NASA and the Soviet Union worked together closely, helping each other obtain the best results. Rather than just flying by the planet like the previous missions, this time the crafts would orbit Mars.

Viking 1 and Viking 2 were the next missions sent to Mars in 1975. These missions consisted of both an orbiter and a lander. They were armed with sophisticated equipment which would perform various experiments, including searching for life. The very first spacecraft to land on Mars was the Viking 1, which landed on Mars on July 20, 1976. Its twin, Viking 2, landed on Mars on September 3, 1976. Each of these spacecraft launched with their orbiter and lander attached to each other. When they each entered Mars' orbit, the lander separated from the orbiter. Each lander landed on different parts of the planet. Many other spacecraft have landed on Mars since these first two in 1976.

Image: NASA/JPL-Caltech

An image taken by Viking 2 of the surface of Mars. Image: NASA/JPL-Caltech

There were no missions sent to Mars for several years after the Viking 1 and Viking 2 missions. Then, in July 1988, two missions were sent by Russia, Phobos 1 and Phobos 2.
The Mars Observer was sent in March 1992. It had two important goals. First, it was going to photograph a mountain on Mars called Cydonia. This mountain looks like a human face, and it was going to prove that it was just a coincidence. Secondly, it was going to search for landing spots for future astronauts. It never carried out its missions, however. Only three days before arriving it broke down and became a useless piece of space junk.

The Pathfinder Sojourner mission was launched on December 4, 1996. It consisted of an orbiter and a lander. The lander was unique in that rather than being stuck wherever it landed, part of it could actually move around like a little remote controlled car. This rover was named Sojourner after NASA conducted a naming contest among school children.

More recently in the summer of 2003, scientists launched two spacecraft that were sent to Mars, one in June, one in July, and each finally landing in January of 2004. These spacecraft each contained a Mars Rover, one named Spirit and the other Opportunity. These rovers are like Sojourner in that they are able to move around on the surface of Mars. They are controlled by scientists here on Earth. But these rovers don't zoom around for fun. They are carefully maneuvered around rocks and other obstacles. They take pictures and record information that is then sent back to Earth. Sadly, Spirit has become stuck somewhere on the surface of Mars. Scientists have not received any contact from Spirit since March of 2010, but they have not given up, they are still trying to communicate with this rover. On the other hand, Opportunity is still alive and exploring many different area of Mars.

It seems that one thing is for sure, there will be many more missions sent to Mars in the future.

UPDATE: On August 5, 2012, at 10:23 p.m. Pacific Daylight Time, the Mars Curiosity* rover landed on Mars. This is an amazing feat considering that Curiosity is about the size of a car! It is 10 feet long (3m), 9 feet wide (2.75m) and 7 feet tall (2.1m), and it weighs 2000 pounds (907kg)! Because of its size, NASA could not land Curiosity on the surface of Mars the same way they had done with other smaller rovers in the past, which was inside a big bubble, basically. Because of its size and weight, Curiosity would be damaged if NASA just dropped it in a bubble to the surface of Mars. They had to devise a whole new way to safely land the rover. The solution was to build a platform and crane system. Curiosity would be attached to the crane underneath the platform. While protected with a heat shield and capsule, the platform/crane system and Curiosity enter Mars' atmosphere. A parachute will deploy to slow down the unit. When cool enough, the heat shield will be discarded. A radar then senses when to detach the platform and Curiosity from the capsule to begin the free fall stage. The radar also senses when to begin firing the retrorockets that will further slow down and stabilize the craft so it doesn't crash into the surface. Then, when the craft reaches an altitude of approximatly 25 feet (7.6m), the crane will lower Curiosity to the surface with cords. Once the crane senses that Curiosity has landed safely, the cords detach from Curiosity and the platform and crane fly away from the rover to crash at a safe distance away so it doesn't interfere with the rover's exploration.

Check out this animation of Curiosity's landing from NASA.

Seen here are model copies of the Mars rovers. The smallest is Sojourner. The
middle size is a model of Spirit and Opportunity. The largest is a model of the
new Curiosity rover. Image: NASA/JPL-Caltech

Curiosity is equipped with several high tech cameras and other sophisticated equipment. It even has a laser that will vaporize rocks and sensors that can read what a vaporized rock is made of. It even has a geology lab on board.

Image: NASA/JPL-Caltech

Image: NASA/JPL-Caltech

Curiosity's mission is to look for conditions, past or present, that are (or were) favorable to life. Its mission is expected to last approximately 23 Earth months, that's 1 year in Mars time. It will be exciting to see what we learn from the Curiosity rover!

*No cats were harmed during this mission, as per the old saying: "Curiosity killed the cat."

Image: NASA/JPL-Caltech

Out of the now 40 attempts to launch missions to Mars, Mars is clearly winning. However, with the successful landing of Curiosity, Earth's score is now 16 to Mars' 24.

What is the future of Mars?
It is quite possible that your decedents 10,000 years from now will live on Mars their entire lives. They will not need space suits because of a science called Terraforming. Terraforming is when you change a planet to make it Earth like. This may sound like science fiction, but it is an actual science, and it is actually possible today. It just takes a long time to accomplish the task.

Long before Mars is terraformed, it will probably be home to scientific colonies living in enclosed shelters built on the planet. These colonies will set the stage for future expeditions to other planets and moons, and will also begin the first steps of terraforming.

Of course, before scientists can live on Mars, we have to make the first step of actually visiting. This is not as easy as it sounds. The technological barriers can be broken in a matter of a few years, but going to Mars is very expensive. Let's hope Congress will see the importance of future exploration by funding these projects allowing us to fulfill our destiny.